Answer to February 22, 1999 Problem |
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Bridge-Crossing Puzzle
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This is supposed to be one of the questions for
potential Microsoft employees. Microsoft expects
you to answer this question in under 5 minutes! "U2" has a concert that starts in 17 minutes and the group members must all cross a bridge to get there. All four men begin on the same side of the bridge. You must help them across to the other side. It is night. There is one flashlight. A maximum of two people can cross at one time. Any party who crosses, either one or two people, must have the flashlight to see. The flashlight must be walked back and forth, it cannot be thrown, etc. Each band member walks at a different speed. A pair must walk together at the rate of the slower man's pace, based on this information:
*Bono - 1 minute to cross For example, if Larry and Bono walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If Larry then returns with the flashlight, a total of 20 minutes will have passed and you will have failed. |
Solution: |
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1. Michael Leatherman | Norfolk, VA |
2. Jia Ran | Rome, Italy |
3. Brian Wempe | Emmaus, PA |